1. Field of Invention
The present invention relates to an ink-jet recording head which has an ejecting port forming plate (often referred as orifice plate hereinafter) where ejecting ports are formed, and relates to a manufacturing method of the ink-jet recording head
2. Brief Description of the Related Art
Today ultra-violet laser light etc., as one of the typical excimer laser light(beam) etc. are used for fabricating ejecting ports of above-mentioned type of the ink-jet recording head. Orifice fabrications have been done by radiating the excimer laser light on a side which leads to liquid paths, of surfaces of resin film, for example, a member for the orifice plate.
However, in the ink-jet recording head manufactured by the above-mentioned method, the resin film is decomposed by the laser light and part of the decomposed products deposit around ejecting ports on the front side of the orifice plate or on the back side of it, for example, as debris(carbon layer), when the excimer laser light is radiated to remove the resin from the spots where ejecting ports are to be fabricated.
When the ink-jet head is constituted by employing the orifice plate fabricated by the above-mentioned method and various recording tests are executed, a physical property particularly wettablity of the surface of the orifice plate varies according to whether the surface bears such deposits or not.
It is generally said that the surface of the orifice plate is preferably to be smoother or more homogeneous with no stagnant ink. However, in the ink-jet recording head where the orifice fabrication is made, such stagnant ink often exists at portions where above-mentioned deposits exist. Due to the stagnant ink, flying trajectories of liquid droplets are not stable and therefore recordings of good quality can not be performed. When such stagnant ink grows large, ejection of ink droplets becomes impossible and sometimes such stagnation leads to disorders that recordings become impossible. Because of such problems, ultra-sonic cleansing or adhesive tape have been employed as a secondary fabricating process after the radiation of the laser light, to remove deposited carbon layers.
By connecting the orifice plate which bears fabricated ejecting ports in above-mentioned way, with a top board where liquid paths are formed, so as to constitute designed alignment, a desired ink-jet ejecting head is obtained. An example of the head constituted by above-mentioned method is shown in FIG. 8.
In FIG. 8 a numeral character 702 represents a top board (also referred as a top board with trenches) where trenches for liquid paths 704 are formed, 701 represents substrate where electro-thermal conversion modules 703 for generating heat to let ink eject are patterned, 705 represents an orifice plate made from resin sheet and 706 represents ejecting ports formed on the orifice plate 705, respectively.
In the head constituted by above-mentioned conventional procedure where carbon deposits are removed via a secondary fabrication after the laser radiation, since stagnant ink is decreased, above-mentioned problems such as unstable ejection of ink droplets etc. are solved to a certain extent. However, it is necessary to remove deposits more completely without failure, in recording heads where ejecting ports are arrayed densely so as to attain a high-density and high-speed recording. Because in such case even small amount of remaining deposits cause the stagnant ink generation, and influence of such deposits on recordings tends to be more sensitive.
In addition, such stagnant ink is sometimes formed by heat influence from the laser radiation and fabrication defects during connecting process of the orifice plate to the top board or deposition of foreign particles.
The present invention is carried out to solve above-mentioned problems. An object of the present invention is to obtain the stagnant ink free and high reliable ink-jet head by removing completely by-products such as carbon deposits etc. generated during the laser fabrication and by preventing the heat influence, defects or foreign particles on the orifice plates, particularly around ejecting ports. Other object of the present invention is to improve printing quality of the ink-jet recordings.
In order to attain the objects mentioned above, the present invention provides the methods from (1) to (7) described hereunder.
(1) In manufacturing method of an ink-jet recording head comprising: a substrate where energy generating elements for ejecting ink are mounted; a top board for forming liquid paths by connecting with portions where the elements mounted; an ejecting port forming plate where ejecting ports for ejecting ink are formed; and
a manufacturing method comprising: a process to paste a sheet member which bears an adhesive layer, capable of being peeled off, at least on one of the sides of the ejecting port forming plate; a process to form the ejecting ports by radiating laser light; a process of peeling off the sheet member after the pasting process of the ejecting port forming plate on the substrate.
(2) A manufacturing method of the ink-jet recording head according to (1), wherein the ejecting port forming plate is constituted by a plate member where at least one of the surfaces of the plate bears a water-repellent layer.
(3) A manufacturing method of the ink-jet recording head according to (1), wherein the sheet members, capable of being peeled off, are applied on the back side or the front side of the ejecting port forming plate or both sides of the plate.
(4) A manufacturing method of the ink-jet recording head according to (1), wherein the sheet member, capable of being peeled off, has enough strength to protect the ejecting ports against mechanical deformation.
(5) A manufacturing method of the ink-jet recording head according to (1), wherein the sheet member, capable of being peeled off has a property to protect the eject ports against thermal influence.
(6) A manufacturing method of the ink-jet recording head according to (1), wherein the sheet member, capable of being peeled off, bears adhesive layers so as to trap by-products during the laser fabrication on the adhesive layers.
(7) The ink-jet recording head is manufactured by one of the methods of (1), (2), (3), (4), (5) and (6).
According to the constitution of the above-mentioned present invention, an adhesive property between the by-product removing tape and the ejecting port forming plate is enhanced by applying removable members such as by-product removing tape etc. on the ejecting port forming plate consisting the orifice plate before fabricating orifices, and by-products are trapped completely by the by-product removing tape which is not peeled off even by the laser during the fabrication.
As mentioned above the present invention enables inventors to trap carbon deposit layers formed, for example, by excimer laser beam, by the by-product removing tape, and to remove the deposited carbon layers completely by peeling off the by-product removing tape. Thermal influence, defects and deposited foreign particles etc. on the surface of the orifice plate during the orifice fabrication process are prevented by peeling off the by-product removing tape after the orifice plate is applied on the substrate. Consequently the present invention enables inventors to supply ink-jet recording heads with high reliability, free from stagnant ink generated by the carbon layers, defects or foreign particles etc.